↑The operand of sizeof can't be a C-style type cast: the expression sizeof (int) * p is unambiguously interpreted as (sizeof(int)) * p, but not sizeof((int)*p).

↑The expression in the middle of the conditional operator (between ? and :) is parsed as if parenthesized: its precedence relative to ?: is ignored.

When parsing an expression, an operator which is listed on some row will be bound tighter (as if by parentheses) to its arguments than any operator that is listed on a row further below it. For example, the expressions std::cout<<a&b and *p++ are parsed as (std::cout<<a)&b and *(p++), and not as std::cout<<(a&b) or (*p)++.

Operators that have the same precedence are bound to their arguments in the direction of their associativity. For example, the expression a=b=c is parsed as a=(b=c), and not as (a=b)=c because of right-to-left associativity of assignment, but a+b-c is parsed (a+b)-c and not a+(b-c) because of left-to-right associativity of addition.

Relative precedence of the conditional and assignment operators differs between C and C++: in C, assignment is not allowed on the right hand side of a conditional operator, so e = a < d ? a++: a = d cannot be parsed. Many C compilers use a modified grammar where ?: has higher precedence than =, which parses that as e =(((a < d)?(a++): a)= d ) (which then fails to compile because ?: is never lvalue in C and = requires lvalue on the left). In C++, ?: and = have equal precedence and group right-to-left, so that e = a < d ? a++: a = d parses as e =((a < d)?(a++):(a = d)).